In image guided minimally invasive therapy, continuous image based guidance may be used while performing patient treatment in a minimally invasive way. A known concept for continuous image based guidance may relate to a rotatable C-shaped arm-based system, which merges continuously a video imaging with an X-ray imaging.
WO 2013/102827 describes a position determining apparatus for determining the position of an interventional instrument within a patient. A spatial relation between positions of a second part of the interventional instrument outside the patient and a first part of the interventional instrument within the patient is determined based on an actual image of the interventional instrument within the patient being preferentially an X-ray image and a provided position of the second part. Once the spatial relation has been determined, the position of the interventional instrument within the patient can be determined, while the interventional instrument is moved within the patient, based on the determined spatial relation and a determined actual position of the second part outside the subject, without necessarily acquiring a further actual image.
Such concept persistently requires having the X-ray detector with the embedded video camera continuously located in its C-shaped arm above, around and below the anatomy of interest in order to track continuously patient and instrument motion. However, the C-shaped arm with the embedded video camera may hinder during the therapy execution due to its large-sized and its position above, around and below the patient.